mediagoblin/tools/template.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011, 2012 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17
  18 import jinja2
  19 from jinja2.ext import Extension
  20 from jinja2.nodes import Include, Const
  21
  22 from babel.localedata import exists
  23 from werkzeug.urls import url_quote_plus
  24
  25 from mediagoblin import mg_globals
  26 from mediagoblin import messages
  27 from mediagoblin import _version
  28 from mediagoblin.tools import common
  29 from mediagoblin.tools.translate import set_thread_locale
  30 from mediagoblin.tools.pluginapi import get_hook_templates
  31 from mediagoblin.tools.timesince import timesince
  32 from mediagoblin.meddleware.csrf import render_csrf_form_token
  33
  34
  35
  36 SETUP_JINJA_ENVS = {}
  37
  38
  39 def get_jinja_env(template_loader, locale):
  40     """
  41     Set up the Jinja environment,
  42
  43     (In the future we may have another system for providing theming;
  44     for now this is good enough.)
  45     """
  46     set_thread_locale(locale)
  47
  48     # If we have a jinja environment set up with this locale, just
  49     # return that one.
  50     if locale in SETUP_JINJA_ENVS:
  51         return SETUP_JINJA_ENVS[locale]
  52
  53     # jinja2.StrictUndefined will give exceptions on references
  54     # to undefined/unknown variables in templates.
  55     template_env = jinja2.Environment(
  56         loader=template_loader, autoescape=True,
  57         undefined=jinja2.StrictUndefined,
  58         extensions=[
  59             'jinja2.ext.i18n', 'jinja2.ext.autoescape',
  60             TemplateHookExtension])
  61
  62     template_env.install_gettext_callables(
  63         mg_globals.thread_scope.translations.ugettext,
  64         mg_globals.thread_scope.translations.ungettext)
  65
  66     # All templates will know how to ...
  67     # ... fetch all waiting messages and remove them from the queue
  68     # ... construct a grid of thumbnails or other media
  69     # ... have access to the global and app config
  70     template_env.globals['fetch_messages'] = messages.fetch_messages
  71     template_env.globals['app_config'] = mg_globals.app_config
  72     template_env.globals['global_config'] = mg_globals.global_config
  73     template_env.globals['version'] = _version.__version__
  74
  75     template_env.filters['urlencode'] = url_quote_plus
  76
  77     # add human readable fuzzy date time
  78     template_env.globals['timesince'] = timesince
  79
  80     # allow for hooking up plugin templates
  81     template_env.globals['get_hook_templates'] = get_hook_templates
  82
  83     if exists(locale):
  84         SETUP_JINJA_ENVS[locale] = template_env
  85
  86     return template_env
  87
  88
  89 # We'll store context information here when doing unit tests
  90 TEMPLATE_TEST_CONTEXT = {}
  91
  92
  93 def render_template(request, template_path, context):
  94     """
  95     Render a template with context.
  96
  97     Always inserts the request into the context, so you don't have to.
  98     Also stores the context if we're doing unit tests.  Helpful!
  99     """
 100     template = request.template_env.get_template(
 101         template_path)
 102     context['request'] = request
 103     rendered_csrf_token = render_csrf_form_token(request)
 104     if rendered_csrf_token is not None:
 105         context['csrf_token'] = render_csrf_form_token(request)
 106     rendered = template.render(context)
 107
 108     if common.TESTS_ENABLED:
 109         TEMPLATE_TEST_CONTEXT[template_path] = context
 110
 111     return rendered
 112
 113
 114 def clear_test_template_context():
 115     global TEMPLATE_TEST_CONTEXT
 116     TEMPLATE_TEST_CONTEXT = {}
 117
 118
 119 class TemplateHookExtension(Extension):
 120     """
 121     Easily loop through a bunch of templates from a template hook.
 122
 123     Use:
 124       {% template_hook("comment_extras") %}
 125
 126     ... will include all templates hooked into the comment_extras section.
 127     """
 128
 129     tags = set(["template_hook"])
 130
 131     def parse(self, parser):
 132         includes = []
 133         expr = parser.parse_expression()
 134         lineno = expr.lineno
 135         hook_name = expr.args[0].value
 136
 137         for template_name in get_hook_templates(hook_name):
 138             includes.append(
 139                 parser.parse_import_context(
 140                     Include(Const(template_name), True, False, lineno=lineno),
 141                     True))
 142
 143         return includes